if (result.rows) {

          for (var i = 0; i < result.rows.length; i++) {

            var row = result.rows.item(i);

            properties[row.name] = row.value;

          }

        }

        return properties;

      }

    }

    export class UpdateStorage implements attached.UpdateStorage {

      private _cachedUpdateStatementsByFile: { [name: string]: string; } = {};

      private _unhandledClosure = (e: SQLError) => this.unhandledSQLError(e);

      private _unhandledTransClosure = (t: SQLTransaction, e: SQLError) => this.unhandledSQLError(e);

      constructor(

        private _db: Database,

        existingFiles: string[]) {

        existingFiles.forEach(file=> this._createUpdateStatement(file));

      }

      update(file: string, property: string, value: string) {

        var updateSQL = this._cachedUpdateStatementsByFile[file];

        if (typeof updateSQL === 'string') {

          this._db.transaction(

            transaction=> transaction.executeSql(

              updateSQL,

              [property, value],

              (transaction, result) => { },

              this._unhandledTransClosure),

            this._unhandledClosure);

        }

        else {

          this._createTable(

            mangleDatabaseObjectName(file),

            transaction => { });

        }

      }

      remove(file: string) {

        this._db.transaction(

          transaction =>

            transaction.executeSql(

              'DROP TABLE "' + mangleDatabaseObjectName(file) + '"',

              [],

              (transaction, result) => { },

              this._unhandledTransClosure),

          this._unhandledClosure);

      }

      unhandledSQLError(sqlError: SQLError) {

        if (typeof console !== 'undefined' && console && console.error)

          console.error(sqlError);

      }

      private _createUpdateStatement(file: string) {

        return this._cachedUpdateStatementsByFile[file] =

          'INSERT OR REPLACE INTO "' +

          mangleDatabaseObjectName(file) +

          '" VALUES (?,?)';

      }

      private _createTable(tableName: string, callback: (transaction: SQLTransaction) => void) {

        this._db.transaction(

          transaction=>

            transaction.executeSql(

              'CREATE TABLE "' + tableName + '" (name PRIMARY KEY, value)',

              [],

              (transaction, result) => callback(transaction),

              this._unhandledTransClosure),

          this._unhandledClosure);

      }

      private _updateEditedCore(transaction: SQLTransaction) {